The mass murder of 22,000 Poles in 1940 by the Soviet secret police at Katyn was one of the most shocking atrocities of World War II. Vehemently denied by the Soviets right up to the collapse of their regime, the massacre has only gradually been acknowledged by Russia, which has yet to satisfy Poland's appeals to declassify the remaining documents or accept the definition of the event as genocide. It has also come to light that Britain (where the Polish government-in-exile resided during the war) knew about Katyn and considered it an incident that might have broken their political alliance with the Soviets—yet the Allies adopted a "suspension of judgment" policy in order to preserve their strategic advantage. Eugenia Maresch, a Pole who was deported with her family to Siberia in 1940 and an expert in Polish-British cooperation during the war, examines this hypocritical deceit of diplomacy, hidden for more than half a century.

"Maresch deftly weaves her way through these political machinations following the Katyn massacre and publishes some fascinating, once-secret Foreign Office and War Cabinet reports and comments from British archives."—Financial Times